Numbers to left of central numbers of the (3,2)-Pascal triangle A029618.

Terms

a(0) =3a(1) =3a(2) =3a(3) =8a(4) =3a(5) =11a(6) =3a(7) =14a(8) =26a(9) =3a(10) =17a(11) =40a(12) =3a(13) =20a(14) =57a(15) =90a(16) =3a(17) =23a(18) =77a(19) =147a(20) =3a(21) =26a(22) =100a(23) =224a(24) =322a(25) =3a(26) =29a(27) =126a(28) =324a(29) =546